Cell for carrying out electrochemical reactions



y 21, 1964 D. G. BRAITHWAITE ETAL 3,141,841

CELL FOR CARRYING OUT ELECTROCHEMICAL REACTIONS 2 Sheets-Sheet 1 Filed July 13. 1960 INVENTORS: DAVID G. BRAITHWAITE JOSEPH S. D'AMICQ PETER L. GROSS WILLIAM HANZEL ATT'YS y 1964 D. a. BRAITHWAITE ETAL 3,141,841

CELL FOR CARRYING OUT ELECTROCHEMICAL REACTIONS Filed July 15, 1960 2 Sheets-Sheet 2 INVENTORS DAVID G. BRAITHWAITE JOSEPH s. D'AMICO PETER L. GROSS WILLIAM HANZEL 'ATT'YS BYWM United States Patent 3,141,841 CELL FOR CARRYING @YUT ELECTRGQHEMECAL REAtITTGNS David G. Braithwaite, (lhicago, Joseph S. DAmico, Westchester, Peter L. Gross, Riverside, and William Hanzel, \Shicago, lit, assignors to Naleo Chemical Company, (lhicago, lllL, a corporation of Delaware Filed July 13, 196i Ser. No. 42,661 8 Claims. (Cl. 204-463) This invention relates to a new and improved cell for carrying out electrochemical reactions, and more particularly to an electrolytic cell having a sacrificial electrode, which is especially useful for the manufacture of tetraethyl lead and other organo metallic compounds.

The term sacrificial electrode refers to an electrode which is eroded or dissolved during the electrolytic process.

One of the objects of the invention is to provide a new and improved cell for making chemical compounds.

Another object of the invention is to provide a new type of structure for cells for carrying out electrochemical reactions in which the reactants are fiowable and one of the reactants consists of solid discrete particles.

A further object of the invention is to provide a new and improved electrolytic cell for making organo metallic compounds by a sacrificial electrode process wherein the cell is closed during its operation and additional quantities of the electrode material are added to the cell continuously or intermittently without permitting significant amounts of the vapors present in the cell to escape to the atmosphere.

Another object of the invention is to provide a new and improved electrolytic sacrificial electrode cell in which the electrolyte is circulated past one electrode and through another electrode of opposite charge.

Another object of the invention is to provide a sacrificial electrode cell which operates efficiently.

A further object of the invention is to provide a sacrificial electrode cell which is constructed of readily available materials which are relatively inexpensive.

An additional object of the invention is to provide an electrolytic cell having a sacrificial electrode composed of particulate solids, the outer boundaries of which are separated from but closely spaced with respect to an electrode of opposite charge.

Another object of the invention is the provision of an electrolytic cell in which an anode composed of individual solid particles of anode material is in contact with a porous membrane, porous diaphragm, or foraminous screen which is a non-conductor of electricity and which is also in contact with the cathode.

Another object of the invention is to provide an electrolytic sacrificial electrode cell in which the electrical resistance of the cell is minimized or greatly reduced by clamping a non-electrically conducting partition such as, for example, a porous membrane, a porous diaphragm or a foraminous screen between the anode and the cathode, and in contact with both of them.

A more specific object of the invention is to provide a new and improved electrolytic cell suitable for the manufacture of tetraethyl lead, tetramethyl lead, and similar compounds.

Other objects and advantages of the invention will appear from the following description in conjunction with the accompanying drawings in which:

FIG. 1 is an elevational view with parts broken away of one type of cell provided in accordance with the invention;

FIG. 2 is a perspective view with parts separated showing another form of cell provided in accordance with the invention;

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FIG. 3 is a fragmentary view of the cell shown in FIG. 1;

PEG. 4 is a fragmentary view of FIG. 2;

FIG. 5 is a fragmentary cross section taken along the line 55 of the cell shown in FIG. 2 illustrating the manner in which the particulate electrode material is supported at the bottom of the cell;

FIG. 6 is a top plan sectional view of the lower part of the cell shown in FIG. '2 taken along the line 6--6;

FIG. 7 is a side view of the lower part of the cell shown in FIG. 2 illustrating the manner in which heat exchange fluid in the cathode is circulated;

PEG. 8 is a fragmentary view illustrating a part of the heat exchange section of FIG. 7 taken along the line 8-8; and

FIG. 9 is a fragmentary plan view of the lower part of the cell of FIG. 2.

In general, the invention comprises a cell for carrying out electrochemical reactions in which a liquid permeable partition which does not take part in the reaction (i.e., is chemically inert to the reactants and the products of reaction) is disposed in said cell and is held against a surface within said cell by a body of particulate solids which constitutes one of the reactants and another reactant in liquid form is circulated through said body of particulate solids and said partition and in contact with said surface. The aforesaid surface substantially corresponds in shape to the boundary surface of said body of particulate solids and the aforesaid partition serves to separate said body of particulate solids from said surface within said cell. This separation should be as close as possible, without permitting contact of the particulate solids with said surface, preferably a fraction of an inch, and in most cases from 0.02 to 0.15 inch. Thus, it permits intimate contact of the reactants and where said surface in the cell is an electrode (e.g., a cathode) the rapid circulation in such a confined space assists in preventing deposits of various reaction products. At the same time the close proximity of the electrodes enhances the electrical efiiciency. The invention also provides means for introducing and withdrawing said liquid and reaction products to and from said cell. An important feature of the invention is the provision of means for introducing additional quantities of said particulate solids to said cell to replenish said solids as they are consumed in the reaction.

In accordance with a more specific embodiment of the invention a cell is provided comprising a container for a body of electrolyte, an electrically conducting surface in said container serving as an electrode and adapted to contact said body of electrolyte, a body of electrically conducting particulate solids in said container serving as an electrode of opposite charge to said first named electrode, and a porous non-electrically conducting partition in said cell between said electrodes in contact with said first named electrode and in contact with the outer boundaries of said body of particulate solids which forms said second named electrode The cell provided in accordance with the invention preferably has means for closing it to the atmosphere during operation so that vapors or gases used as reagents during the operation of the cell in carrying out chemical processes, or solvents used in such processes, or products or by-products of such processes, cannot escape and contaminate the surrounding atmosphere.

Additionally, the electrolytic cell provided in accordance with the invention preferably has as one of its features means to add additional quantities of the anode material to said cell while it is operating and without permitting significant quantities of gases or vapors within the cell to escape to the atmosphere.

A further and optional feature is the provision of a cell of the type described having grooves in the cathode, preferably running in a direction generally parallel to the direction of flow of the electrolyte to facilitate circulation of the liquid electrolyte in contact with the cathode area so as to control both temperature and cathode reaction.

In the drawings, FIGS. 1 and 2 illustrate two different cells each embodying the same general principles. FIG. 1 illustrates one embodiment of the invention in which the electrolytic cell consists of an iron pipe 1 which is provided at one end with a flange 2. Adjacent and in contact with the inside of the pipe 1 is a foraminous liquid permeable screen 3 which is electrically nonconducting and preferably consists of one or more layers of glass filament screen having openings therein sulficiently large to permit the flow of a liquid electrolyte therethrough but sufliciently small to prevent the anode material from passing through the openings or meshes of the screen to contact the inner surface of the pipe 1.

In the center of the cell is an anode rod 4 which is connected at one end 5 to a source of positive electricity indicated at a. In the particular cell shown the rod 4 is held in place by means of a rubber stopper indicated at 7 which also serves to support the anode material 8.

The anode material 8 consists of pellets or particles of a solid anode substance. For example, when the cell is isued to make tetraethyl lead, or tetramethyl lead or other organo lead compounds, the anode material is composed of lead pellets. These pellets may be spherical, elongated or of any other shape and of any suitable size sufiiciently large to be contained within the cell and separated from the inner surface of the pipe 1 by means of the foraminous member 3. The size of the pellets is such that they will drop down vertically between the rod 4 and the inner surface of the foraminous member 3. The foraminous member 3 is in contact with the cathode surface and the adjacent pellets and, in effect, is clamped therebetween.

The cell is provided with means forming an opening 9 and other means forming an opening 10 in the lower and upper portions of the cell to serve as either an inlet or an outlet for the electrolyte. In conventional operation the electrolyte is introduced through the opening 9 and after circulating through the cell passes out through the opening 10. The electrolyte is preferably recirculated externally through a pipe, not shown, with the assistance of a pump, not shown, and returned to the cell through the opening 9, either continuously or intermittently. The recirculating electrolyte provides agitation in the cell and assists in removing chemical deposits from the inner parts of the cell such as the rod 4, the anode material 8, the partition 3 and the cathode wall.

In the embodiment shown in FIG. 1 the lower part of the cell is sealed by means of a tubular glass member 11 which is sealed in any suitable'manner to the outside of the pipe 1 and which is provided at its outer end with a rubber stopper 12 through which the anode rod 4 passes.

The upper part of the cell is sealed by means of a tubular glass member 13 which is provided with a flange 1 the latter being sealed with respect to the flange 2 by means of a suitable gasket 15.

The upper part of the tubular member 13 is provided iwth a valve 16 which can be operated by hand from a valve wheel 17 or can be operated automatically in any suitable manner. The tube 18 extends from the valve 16 to a suitable storage chamber for the anode material generally indicated in the form of a funnel at 19. The storage chamber can, if desired, be sealed from the atmosphere in any suitable manner. By opening the valve 16 pellets of anode material in the funnel 19 are discharged through the tubes 18 and 13 to the interior of the cell 1 to replenish the anode material which has previously been used up by the electrolyzing process.

The inlet and outlet openings 9 and 16 are preferably made of a metal corresponding to the metal of the pipe 1, e.g., iron or steel.

A source of negative electricity is connected by any suitable means 20 to the inlet pipe 9 or to any part of the pipe 1. The pipe 1, therefore, serves as a cathode and it is a desirable feature of the present invention that this portion of the cell can be made from iron, steel and other relatively inexpensive materials of construction.

In the cell of FIG. 1 it is preferable to form the rod 4- of the same substance as the anode material. Thus, where the cell is employed to make tetraethyl lead or other organo lead compounds, the anode material 8 would consist of lead pellets and the rod 4 would also becomposed of lead. It is not absolutely essential, however, that the rod 4 be composed of the same material as the anode material. It can be formed from a material which merely conducts the current to the anode material and is not itself dissolved by the electrolyzing process.

In the modification of the invention shown in FIG. 2 the electrolytic cell is composed of three compartments 21, 22 and 23. The inner compartment 21 is the electrolyzing compartment and the pellets of anode material 24 as shown in FIG. 4, are contained in this compartment. The pellets 2d are separated from the side walls of the compartment by a foraminous screen layer 25 composed of glass filaments, a second layer of foraminous screen material 26 composed of nylon filaments, and a third layer of foraminous screen material 27 composed of glass filaments. The layer 27 is in contact with the interior of all four sides of the inner compartment 21. The layer 25 is in contact with outer boundaries of the pellets 24 on all four sides. Thus, the weight of the pellets 24 clamps the screen layers 25, 26 and 27 against the cathode surface of compartment 21.

To assist in holding the layers of foraminous screen in place and to keep them from falling down into the cell as the reaction progresses and additional quantities of anode material are added, the upper part of the cell is provided with a flange 28 as shown in FIG. 4, and the layers of foraminous screen material are clamped in place between the flange 28 and a flange 29 on the closure member 30. When the cell is ready to operate and where it is used to manufacture chemical substances of a toxic nature, the closure member 30 is applied to the lower part of the cell 31 and the two members are fastened together by means of threaded bolts 32, or in any other suitable manner, and preferably with a gasket 33 interposed between the flanges 23 and 29 in such a way as to act as a seal and prevent the escape of vapors or gases from the interior of the cell.

The outer compartments of the cells 22 and 23 are heat exchange compartments and can be used to hold a heating or cooling fluid during the operation of the cell. In the manufacture of tetraethyl lead, for example, the reaction is exothermic and it is desirable to pass a circulating cooling fluid through the compartments 22 and 23 while the cell is in operation. The cooling fluid, for example, may be benzene, kerosene or any other hydrocarbon. It can also be a conventional cooling fluid, such as water, alco hol, diethylene glycol, or the like.

In the embodiment of the drawing shown in FIG. 2, the heat exchange fluid is introduced into the compartments 22 and 23 by means of pipes 34 and 35 which connect to a pipe 36, the latter in turn connects to a pipe 37 which is connected to a source of supply for the heat exchange fluid. Valves 38, 32 and 40 control the flow of the heat exchange fluid.

The heat exchange fluid which is introduced into the compartments 22 and 23 from the inlet pipe 37 can be removed and recirculated, if desired, through pipe 41 controlled by valve 42 in the lower part of compartment 22 and pipe 43 controlled by valve 44 in the lower part of compartment 23. Pipes 42 and 43 discharge into pipe 45 which connects to pipe 46 controlled by valve 47.

The electrolyte is preferably introduced into the compartment 21 through pipe 43 controlled by valve 49. An electrically conducting plate 50 is preferably positioned in the middle of chamber 21 and is electrically connected by means of a stainless steel rod 51 or other suitable means to a cable 52 which in turn is connected to a source of positive potential. The anode plate 50 conducts electricity to pellets of the anode material 24 and is supported on a bed of electrically non-conducting material, such as glass balls or beads 53 in a manner shown in FIG. 5. The electrolyte can be withdrawn from the center compartment 21 through an outlet 54 controlled by valve 55.

The sides of the compartments 21, 22 and 23 are composed of an electrically conducting material, preferably iron or steel, and a source of negative potential is connected thereto at any suitable point by any suitable means as, for example, by means of a cable 56. Each of the heat exchange compartments 22 and 23 is provided with a staggered arrangement of metal bars 57 as shown in FIG. 8 which define passageways for the heat exchange fluid so that it is circulated in each heat exchange compartment in a predetermined uniform manner as shown by the arrows in FIG. 7.

The level of the glass balls or beads 53 in the electrolyzing chamber 21 is indicated by the dotted line 58 in FIG. 7. The foraminous screen composed of members 25, 26 and 27 preferably extends below the upper part of the layer of glass balls or beads 53 so that the glass balls or beads assist in holding the screen layers in place against the walls of the chamber 21.

The plates 57 which define the passageways in the heat exchange chambers 22 and 23 are held in place by means of machine screws 59, rivets or other suitable means.

As shown in FIG. 2 the closure member 30 is connected to a pipe 50 controlled by a valve 61 which connects through a pipe 62 to a storage chamber 63 for the anode material. When the valve 61 is closed the anode material remains in the chamber 63 and when it is opened the anode material falls by gravity into the center compartment 21 of the lower part of the cell 31. The pressure gauge 64 and a temperature indicator 65 are provided to indicate the temperature and pressure within the cell. The cell can be operated at varying temperatures and pressures, depending upon the particular electrolyzing process.

While the cell of the present invention can be used in various types of processes involving electrolyzing an electrolyte between a cathode and a sacrificial anode, it is especially useful in processes of preparing organo metallic compounds by electrolyzing between a cathode and a sacrificial metal anode an electrolyte capable of liberating free organic radicals which combine chemically with the metal of said anode. Cells of the type described herein are particularly useful for the manufacture of tetraethyl lead by electrolyzing a Grignard reagent in which the organic radicals are ethyl radicals, in an anhydrous solvent for the Grignard reagent, using a lead anode material and mild steel cathodes.

As an example of the construction and operation of the cell shown in FIG. 1 a cell of this type was constructed in which the cathode portion was an iron pipe about 30 inches long with one-half inch flange openings welded on opposite sides of the pipe 24 inches apart to form the inlet and outlet openings 0 and for introducing and withdrawing the electrolyte. The center of the bottom inlet opening was about 2 inches from the bottom of the cell and the center of the top outlet opening was about 4 inches from the top of the cell. Three layers of fiberglass window screening were used as a liner on the inside of the pipe to separate the cathode from the lead pellets which formed the anode material. The total thickness of these three layers was around 0.040 inch. The anode rod 4 was a round lead rod 0.26 inch in diameter.

The area of the cathode was equal to the inside area of the pipe 1 and this area was approximately 92 square inches. The area of the inside of the fiberglass screening tube was approximately 84.25 square inches. The distance between the anode and cathode as previously indicated, was 0.040 inch. The available volume Within the cell was 18.65 cubic inches. The space between the rod and the fiberglass screen was 0.369 inch which was the equivalent of about 2% of the lead pellets employed as an anode material. The cell was charged with 2093 grams of lead pellets.

An ethylmagnesium chloride Grignard solution was prepared as a solution in dibutylcarbitol in a concentration of about 2.25 moles of Grignard reagent per liter of solution and a predetermined quantity of this solution was circulated through the cell as the electrolyte. In the cell shown in FIG. 1 this solution was circulated through an external heat exchange system, not shown, which maintained a predetermined operating temperature. Sufiicient ethyl chloride was added to produce a predetermined ethyl chloride concentration and enough ethyl chloride was added during operation of this cell to maintain this concentration. The Grignard solution was transferred to the system under nitrogen pressure and about 8 liters was used. The solution was circulated in the cell until the desired temperature and pressure conditions were obtained.

When an operating temperature of F. was reached, in the system, electrolysis was started. Any gas which Was formed was bled off from the recirculating electrolyte externally of the cell. The initial system operation conditions were:

Temperature 100 F.

7.5 pounds per square inch gauge Pressure (p.s.i.g.) Flow rate of the electrolyte 1.5 gallons per minute (g.p.m.). Voltage 28 volts direct current. Current flow 4.35 amperes. Pressure drop through the cell 8 p.s.i.g.

After 37.25 ampere hours of operation the flow rate was increased to 2.25 g.p.m. After 104.5 ampere hours of operation the flow rate was reduced to 1.25 g.p.m. Prior to this reduction in flow rate, the flow rate through the system slowly increased to 3 g.p.m. After ampere hours of operation the cell was tapped on the outside to cause the lead pellets to flow down into the cell. This immediately caused a slight increase in the pressure drop and also an increase in the current flow. After 177 ampere hours grams of lead pellets were added to the cell. A nitrogen purge was used during the addition. At 185 ampere hours the cell was again tapped and the lead level dropped again causing the pressure drop and current flow to increase. The ethyl chloride concentration was maintained at about 8.6% by weight of the electrolyte. Liquid samples taken from the recirculating electrolyte indicated that the current efficiency was about The operation of the cell was continued for 317 ampere hours and tetraethyl lead was recovered from the electrolyte.

The specific kinds and proportions of reactants used in the foregoing example for the preparation of tetraethyl lead are illustrative only and do not form a part of this invention. The method used in recovering the product from the electrolyte likewise does not form a part of this invention.

It will be recognized that the invention is susceptible to considerable variation and modification in the manner of its practical application. For example, the type of material used to form the partition which separates the anode from the cathode is subject to variation. In the pipe cell described in FIG. 1 an ordinary window screen type of 16 mesh glass fiber screen coated with a vinyl plastic rolled to form three layers was used as the partition member. In the embodiment illustrated in FIGS. 2, 4, 5, 6, 7 and 8, the partition consisted of two layers of the same type of glass fiber window screen material with an intervening layer of 100 mesh nylon filter cloth. Other s arper 2 kinds of chemically inert non-electrically conducting membranes, diaphragms, screen and the like in single or multiple layers, can be used which are permeable to the electrolyte. For example, a metal screen coated with Teflon or polyethylene canbe employed as the member 3 or as a substitute for the members 25, 26 and 27.

In the cell shown in FIGS. 2, 4, 5, 6, 7, 8, and 9 the operation of the cell is similar to the operation already explained with respect to the cell of FIG. 1. In this cell heating or cooling of the electrolyte is effected in the cell itself. It will be understood that the anode plate 5% can be larger or smaller in size. The purpose of this plate is to contact a sufiiciently large number of the pellets of anode material to produce a relatively uniform current flow. In the operation of this cell the liquid electrolyte is introduced through the inlet pipe 4? controlled by valve 49 and is removed through the outlet 54 controlled by valve 55. The heat exchange fluid is preferably introduced through the inlet pipe 37 controlled by valve 40 and is removed through the outlet 45 controlled by valve 4?. Pressures and temperatures are indicated by the gauges 64 and 65, respectively. Additional quantities of anode material are introduced from the storage reservoir 63 through the pipe 62, valve 61 and pipe 60. Any suitable means, not shown, may be employed within the cell to direct the anode material from the pipe 60 to the inner compartment 21 in order to fill this compartment with the pelleted anode material uniformly- FIG. 9 illustrates channels or grooves 66 which are placed in the cathode wall of the cell of FIG. 2 and preferably run in a direction generally parallel to the direction of flow of the electrolyte to facilitate circulation of the liquid through the cathode area and to assist in controlling temperature and reactions which occur at the cathode. These grooves run vertically for distances corresponding to the depth of the bed of anode material. In the manufacture of tetraethyl lead by electrolyzing a lead anode in a solution of ethylmagnesium chloride Grignard reagent in an anhydrous solvent such as dibutylcarbitol, one reaction that can occur at the cathode is the formation of magnesium and it is desirable for the purpose of the present invention to provide grooves in the cathode to facilitate circulation and disperse mag nesium, lead, or other substances which may form or tend to deposit in the cathode area.

It will be recognized that similar grooves can also be placed in the cathode wall of a continuous tube such as that shown in the cell of FIG. 1. Furthermore, the grooves can be spirally arranged, or can be ararnged in any other desired flow pattern.

The invention provides a new type of cell in which the electrical resistance of the cell is minimized or greatly reduced by clamping a non-electrically conducting liquid permeable partition such as, for example, a porous membrane, a porous diaphragm or a foraminous screen between the anode and the cathode and in contact with both of them. This structure makes it possible to reduce the distance between the anode and the cathode to a few hundredths of an inch and good results have been obtained in cells of the type described when the distance between the surface of the cathode and the outer boundaries of the anode pellets has been around 0.03 to 0.05 inch. It will be understood that this distance can be smaller or greater but the smaller the distance the less the electrical resistance and the more efficient the operation of the cell.

The structure of the cell also makes it possible to introduce one of the reacting materials while the cell is being operated and without opening it. This is extremely important in the manufacture of tetraethyl lead which is an exceedingly toxic material. To facilitate proper distribution of the pellets or other particulate solid material in the cell, the cell may be tapped or shaken, either continuously or at intervals.

Cells of the type described herein may be operated as single cells or in series. Where the cells are operated in series the liquid electrolyte can be passed from one cell to another in succession.

The invention is hereby claimed as follows:

1. A cell for making organo metallic compounds by electrochemical reaction comprising a container adapted to hold a body of liquid, a body of particulate metallic solids in said container constituting a reactant for carrying out said electrochemical reaction, said container having an electrically conducting inner surface generally corresponding in shape to the boundary surface of said body of particulate solids, a liquid permeable electrically non-conducting partition, in contact with said first mentioned surface and with the outer boundaries of said body of particulate solids, said partition being a foraminous material having openings therein which are sufficiently large to be permeable to said liquid but which are sufiiciently small to prevent said particulate solids from contacting said first mentioned surface, said surface being substantially co-extensive with one side of said partition, means to cause said liquid to flow through said body of particulate solids and through said partition along the interface between said partition and said first mentioned surface, and means for maintaining different electrical potentials on said particulate solids and said surface.

2. A cell for making organo metallic compounds by electrochemical reaction comprising a container adapted to hold a body of liquid, a body of particulate metallic solids in said container constituting a reactant for carrying out said electrochemical reaction, said container having an electrically conducting inner surface generally corresponding in shape to the boundary surface of said body of particulate solids, a liquid permeable electrically non-conducting partition, in contact with said first mentioned surface and with the outer boundaries of said body of particulate solids, said partition being a foraminous material having openings therein which are sufficiently large to be permeable to said liquid but which are sufficiently small to prevent said particulate solids from contacting said first mentioned surface, said surface being substantially co-extensive with one side of said partition, means to cause said liquid to flow through said body of particulate solids and through said partition along the interface between said partition and said first mentioned surface, means to add additional quantities of said particulate solids to said body of particulate solids as an electrochemical reaction progresses in said cell, and means for maintaining different electrical potentials on said particulate solids and said surface.

3. A cell for making organo metallic compounds by electrochemical reaction comprising a container adapted to hold a body of liquid, a body of particulate metallic solids in said container constituting a reactant for carrying out said electrochemical reaction, said container having an electrically conducting inner surface generally corresponding in shape to the boundary surface of said body of particulate solids, a liquid permeable electrically non-conducting partition, in contact with said first mentioned surface and with the outer boundaries of said body of particulate solids, said partition being a foraminous material having openings therein which are sufficiently large to be permeable to said liquid but which are sufficiently small to prevent said particulate solids from con tacting said first mentioned surface, said surface being substantially co-extensive with one side of said partition, means to cause said liquid to flow through said body of particulate solids and through said partition along the interface between said partition and said first mentioned surface, means to direct the flow of said liquid along said surface, and means for maintaining different electrical potentials on said particulate solids and said surface.

4. A cell for making organo metallic compounds by electrochemical reaction comprising a container adapted to hold a body of liquid, a body of particulate metallic solids in said container constituting a reactant for carrying out said electrochemical reaction, said container having an electrically conducting inner surface generally corresponding in shape to the boundary surface of said body of particulate solids, a liquid permeable electrically non-conducting partition, in contact with said first mentioned surface and with the outer boundaries of said body of particulate solids, said partition being a foraminous material having openings therein which are sufliciently large to be permeable to said liquid but which are sufficiently small to prevent said particulate solids from contacting said first mentioned surface, said surface being substantially co-extensive with one side of said partition, means to cause said liquid to flow through said body of particulate solids and through said partition along the interface between said partition and said first mentioned surface, said last named means comprising an inlet for said liquid communicating with one part of said body of particulate solids and an outlet for said liquid communicating with a part of said body of particulate solids remote from said first part, and means for maintaining different electrical potentials on said particulate solids and said surface.

5. A cell as claimed in claim 1 in which said electrically conducting surface constitutes a cathode and said particulate solids constitute the anode.

6. A cell as claimed in claim 1 in which said electrically conducting surface of said container is of ferrous metal and said particulate solids consist essentially of lead.

7. A cell as claimed in claim 1 in which said electrically conducting surface of said container is tubular.

8. A cell as claimed in claim 1 which contains a chamber in contact with the surface of said container opposite the surface in contact with said forarninous material, said chamber comprising means for the introduction and withdrawal of a heat exchange medium.

References Cited in the file of this patent UNITED STATES PATENTS 1,253,560 Anderson Jan. 15, 1918 1,874,748 Henderson Aug. 30, 1932 2,104,812 Phillips Jan. 11, 1938 2,503,863 Bart Apr. 11, 1950 FOREIGN PATENTS 71,230 Norway Nov. 4, 1946 

1. A CELL FOR MAKING ORGANO METALLIC COMPOUNDS BY ELECTROCHEMICAL REACTION COMPRISING A CONTAINER ADAPTED TO HOLD A BODY OF LIQUID, A BODY OF PARTICULATE METALLIC SOLIDS IN SAID CONTAINER CONSTITUTING A REACTANT FOR CARRYING OUT SAID ELECTROCHEMICAL REACTION, SAID CONTAINER HAVING AN ELECTRICALLY CONDUCTING INNER SURFACE GENERALLY CORRESPONDING IN SHAPE TO THE BOUNDARY SURFACE OF SAID BODY OF PARTICULATE SOLIDS, A LIQUID PERMEABLE ELECTRICALLY NON-CONDUCTING PARTITION, IN CONTACT WITH SAID FIRST MENTIONED SURFACE AND WITH THE OUTER BOUNDARIES OF SAID BODY OF PARTICULATE SOLIDS, SAID PARTITION BENG A FORAMINOUS MATERIAL HAVING OPENINGS THEREIN WHICH ARE SUFFICIENTLY LARGE TO BE PERMEABLE TO SAID LIQUID BUT WHICH ARE SUFFICIENTLY SMALL TO PREVENT SAID PARTICULATE SOLIDS FROM CONTACTING SAID FIRST MENTIONED SURFACE, SAID SURFACE BEING SUBSTANTIALLY CO-EXTENSIVE WITH ONE SIDE OF SAID PARTITION, MEANS TO CAUSE SAID LIQUID TO FLOW THROUGH SAID BODY OF PARTICULATE SOLIDS AND THROUGH SAID PARTITION ALONG THE INTERFACE BETWEEN SAID PARTITION AND SAID FIRST MENTIONED SURFACE, AND MEANS FOR MAINTAINING DIFFERENT ELECTRICAL POTENTIALS ON SAID PARTICULATE SOLIDS AND SAID SURFACE. 